Spray gun



March 31, 1942. w. F. MCKEE 2,277,928

SPRAY GUN Filed Sept. 20, 1940 z; 37 3/ w x 7 .5? FIG.2.

60 v 62 1NVENTOR.

BY WILLIAM F. McKEE ATTORNEY.

Patented Mar. 31, 1942 SPRAY GUN William F. McKee, Belleville, Ill.,

Cortner M.

assignor to Hardy, Henderson, Ky.

Application September 20, 1940, Serial No. 357,529

11 Claims.

This invention relates generally to fluid spraying apparatus and, more particularly, to a certain new and useful improvement in spraying apparatus of the type commonly designated spraygun.

My invention has for its primary object the provision of a spray-gun uniquely constructed for utilizing compressed air or other motive fiuid not only for effecting spray-discharge, but also for scavenging the nozzle and spray-discharge chambers and ducts upon cessation of spray-discharge, whereby the gun is substantially automatically self-cleaning.

My invention has for a further object the provision of a spray-gun so constructed as to build up motive pressure for automatically in the nature of self-priming facilitating spray-discharge.

My invention has for another object the provision of a spray-gun, which is simple and inexpensive in constructio compact in design, capable of being readily disassembled for repair or the replacement of parts, easily and conveniently manipulated and controlled by the operator, and highly satisfactory and eflicient in the performance of its intended functions.

And with the above and other objects in view, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawing- Figure 1 is a reduced schematic view, partially in section and partially in perspective, of a fluidspraying system including a. spray-gun constructed in accordance with and embodying my present invention; and

Figure 2 is a longitudinal sectional view of the spray-gun.

Referring now in more detail and by reference characters to the drawing, which illustrates a preferred embodiment of my invention, the body of the spray-gun is preferably in the form of a casting A, which includes a generally flat rectangular handle-providing block a, conjoined to and surmounting which is a suitably extended tubular portion or so-called control-barrel b, and, in turn, surmounting, and, by means of suitable spaced so-called necks l, I, conjoined to, the barrel b, is a discharge-barrel c.

The control-barrel b, suitably intermediate its opposite ends, has a preferably cylindrically reduced chamber, as at 2. Outwardly from, and n opposite sides of, the chamber 2, the barrel b is counterbored, as at 3 and 4.

shown, is a tubular shell 1,

gasket 6 disposed against the annular shoulder provided by one end of the wall of chamber 2, as V the end-wall 5 of which has a central aperture, as at 8, concentrically surrounded by a rearwardly presented annular valve-seat-forming ring or shoulder 9. Within the barrel b atthe opposite or forward end of the shell 7, is a second ring-gasket l0, and threaded into the barrel b to impinge the gasket I0, is a gland-nut H equipped with a conventional packing-ring l2 and packing-nut l3.

Mounted snugly upon the casting A for slidable movement along and over the forward end of the control-barrel b, is an open-ended cylindrical so-called trigger-cap d having a tubular side wall It and a forwardly presented end-wall I5.

Formed on the wall I4 of cap it and normally disposed in convenient adjacence to the block a, is a downwardly presented trigger it.

Secured at its forward end, as by means of a screw l1, upon the inner face of the end-wall l5 and lengthwise extending slidably through the packing-nut l3, ring l2, gland-nut H, and aperture 8 of shell end-wall 5, is a valve rod l8, which terminates at its rearend within the chamber 2 and is there provided with a valve plug l9 having forwardly and rearwardly presented washers 20 and 20, respectively, the rod l8 and trigger-cap d being normally biased forwardly by means of a compression spring 2| coiled on rod l8 for endwise impinging the outwardly presented face of the packing-nut l3 and the inner face of the cap end-wall I 5 to snugly seat the valve-washer 20 against the shoulder 9 and thereby close the shell-aperture 8, all as best seen in Figure 2 and for purposes presently fully appearing.

Similarly pressed into the opposite or rear bore 4 and having an end-wall 22 impinging a second sealing rear-gasket 23 disposed against the rear annular shoulder provided by the opposite end of the wall of chamber 2, also as shown, is an intermediate tubular insert 24 having an axial passage 25 and a rearwardly presented counterbored chamber 26. At its forward end, the passage 25 is adapted for communication with the chamber 2, andupon the forward face of its end-wall 22, the tubular member 24 is provided with a forwardly presented concentric shoulder 21 for seat-forming engagement with the rearwardly presented washer 20' of valve-plug 19.

Also pressed into the bore 4 and having an end-wall 28 impinging a sealing ring-gasket 29 disposed upon the rear end-face of the member or insert 24, is a second tubular shell 30, the end-wall 28 of which has a central aperture 3| surrounded by a forwardly presented concentric seat-forming ring or shoulder 32.

Within the barrel b at the opposite or rearward end of the shell 30, is a second ring-gasket 33, and threaded into the barrel b to impinge the gasket 33, is a second gland-nut 34 likewise equipped with a conventional packing-ring 35 and packing-nut 36.

Mounted snugly upon the casting A for slidabl movement along and over the rearward end of the control-barrel b, is a second open-ended cylindrical cap e having a tubular wall 31 and a rearwardly presented end-wall 38.

Secured at its rear end, as by means of a screw 39 centrally upon the inner face of the end-wall 38 and lengthwise extending slidably through the packing-nut 36, packing-ring 35, gland-nut 34,

.and aperture 3| of shell end-wall 28 and terminating at its forward end within the chamber 26, is a second valve-rod 40 provided at its forward end with a valve-plug 4| having a rearwardly presented washer 42 for seating on the ring 32 for closure of the opening or aperture 3|, the rod 40 and cap e being normally biased rearwardly by means of a compression spring 43 coiled on rod 49 for yieldingly endwise impinging the rear face of th packing-nut 36 and the inner face of the cap end-wall 38 for snugly seating the washer 42 against the shoulder 32 for closure of the shellaperture 36, all as best seen in Figure 2 and for purposes presently fully appearing.

Suitably intermediate its opposite ends, the discharge-barrel c is formed or provided with a relatively thick transverse wall 44 and is thereby divided to include a relatively long front chamber 45 and a correspondingly short rear chamber 46, the wall 44, in turn, being axially bored and counterbored in the provision of a passage 41 and a forwardly presented concentric recess, as at Seated in the recess 48, is a ring-gasket 49, and snugly pressed at its rear end into the recess 48 and in impinging relation with the gasket 49, is a liquid conduit tube 50, which extends axially through the forward chamber 45 and is provided at its forward end with a diametrally enlarged head in turn, provided with a forwardly projecting conical tip 52 having upon its outer face a plurality of longitudinally extending radially projecting fins 53.

Threaded upon the forward end-portion of the discharge barrel C, is a nozzle 1 internally contoured for snug-fitting engagement with the fins 53 and provided with an axial discharge-orifice 54 aligned with the bore of the tube 59.

Likewise threaded upon the rear end-portion of the discharge-barrel c, is a closure end-cap g, thread-seated in the end-wall 55 of which is a throttling needle 56 having a forwardly presented conical tip 51 for seated disposition within the aperture or passage 41 of wall 44. Preferably disposed on the shank of the needle 56 for impinging the outer face of cap end-wall 55, is a locking nut 51, also as best seen in Figure 2 and for purposes presently fully appearing.

The handle or grip-portion a is suitably provided longitudinally with spaced channels 58, 59, respectively opening at one end into the chambers 2 and 26 and at the other end having communication, by means of threaded nipples 60, with conduit tubes 6|, 62, in turn, respectively connected to a compressed air or other motive fluid supply tank B and a liquid-supply tank C.

Finally, the chamber 45 is in communication with the interior of the shell 1 by means of a duct or passage 63 extending through the neck I and side-wall of the shell 1, and the chamber 46 is communicatingly connected with the interior of the shell 39 by means of a duct or passage 64 extending through the neck I and side-wall of the shell 30.

When th apparatus as it may be said, the valve-plugs |9, 4|, will be yieldingly seated against the respective valveseats 9, 32, and compressed air or other motive or actuating fluid from the tank B will accordingly flow through the tube 6| and channel 58 into chamber 2 and from chamber 2 through passage 25, chamber 26, channel 59, and tube 62 into the tank C, such fluid bubbling through the liquid or spray-material contained therein and imposing or building up a pressure up n the upper face of the contained sprayed-material substantially equivalent to the pressur in the tank B.

In manipulating the gun, the operator grasps the body A by the handle or grip-portion a, placing his index finger, for example, around the trigger l6. Upon pulling the trigger l6 and attached cap d rearwardly against the tension of spring 2|, the valve-plug l9 will be shifted rearwardly away from the valve-seat 9 and into seated engagement against the valve-seat 21, when compressed air from the tank B will then flow through the aperture 8, shell 1, and passage 63 into the chamber 45 of the discharge-barrel c and thence outwardly through the channels between the nozzle-fins 53 and through the discharge-orifice 54, thereby setting up suction through the tube 56.

Simultaneously, the cap e is pressed forwardly with the thumb, for instance, and the valve-plug 4| unseated to open the shell-aperture 3|. The pressure above the surface of the spray-material contained within the tank C will thereupon automatically in the nature of self-priming force such material upwardly through the tube 62 and channel 59 into the chamber 26 and from chamber 26 through valve-opening 3|, shell 30, and passage 64 into the chamber 46, and thence through tube 50 into the nozzle f, where it is caught up in the stream of compressed air flowing through the orifice 54 and atomized in the formation of a spray.

Whenever the operator desires to suspend or cease spraying operations, the trigger l6 and endcap e may be released, whereupon the valveplugs l9, 4|, yieldingly return to original positions and cut off the passage of air and spraymaterial through the gun. It will be noted that the compressed air will then again flow through the communicating passages and chambers 6|, 56, 2, 25, 26, 58, and 62 into the liquid tank C, blowing back into the tank C whatever column of liquid may be left entrained in the chamber 26, channel 59, and conduit 62. Thereupon, the gun may be directed away from the work and the thumb-cap e pressed forwardly to permit compressed air to flow through the aperture 3|, shell 39, and passage 64 into the chamber 46 and through the tube 50, expelling or scavenging any residual spray-material and thereby obviating clogging and cleaning the gun of any such spraymaterial for a subsequent efiicient spraying operation.

It will further be noted that an experienced operator may readily accomplish the scavenging of residual spray-material from the discharge system of the gun simply by retaining his thumb upon the cap e for a very slight period of time is not in use or normallysubsequent to release oi the trigger I6. Thus the valve-plug l9 will close in advance of the valve-plug 4|, so that compressed air from the tank B will momentarily course through the discharge passages of the gun and expel any residual spray-material.

It will, of course, be evident that the liquid density of the spray-material may very readily and conveniently be controlled by suitable adjustment of the throttling needle 56.

The gun fulfills in every respect the objects stated, and it should be understood that changes in the form, construction, arrangement, and combination of the several parts of the gun and associated members of the spraying apparatus may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A spray-gun including, in combination, a first barrel having a discharge-nozzle and chambers normally for separate motive fluid and spray-material discharge into the nozzle, a second barrel fixed to the first barrel and having a chamber adapted for communication with a source of motive fluid supply, ducts disposed on opposite sides of the second barrel chamber and having communication with the first barrel chambers respectively, and means for communicating the chamber of the second barrel with one or the other of said ducts for selectively directing motive fluid into either of the first barrel chambers for nozzle-discharge.

2. A spray-gun including, in combination, a first barrel having a discharge-nozzle and chambers normally for separate motive fluid and spray-material discharge into the nozzle, a second barrel fixed to the first barrel and having a chamber adapted for communication with a source of motive fluid supply, ducts disposed on opposite sides of the second barrel chamber and having communication with the first barrel chambers respectively, and means comprising a valve shiftable in the chamber of the second barrel for communicating the same with one or the other of said ducts for selectively directing motive fluid into either of the first barrel chambers for nozzle-discharge.

3. A spray-gun including, in combination, a first barrel having a discharge-nozzle and chambers normally for separate motive fluid and spray-material discharge into the nozzle, a second barrel fixed to the first barrel and having a chamber adapted for communication with a source of motive fluid supply, ducts disposed on opposite sides of the second barrel chamber and having communication with the first barrel chambers respectively, and means comprising oppositely disposed valve-seats and a yieldingly shiftable valve in the chamber of the second barrel for selectively communicating said latter chamber with one or the other of said ducts for selectively directing motive fluid into either of the first barrel chamber for nozzle-discharge.

4. A spray-gun including, in combination, a first barrel having a discharge-nozzle and a chamber for motive fluid discharge into the nozzle, a second barrel fixed to the first barrel and having a first chamber adapted for communication with a source of motive fluid supply and a second chamber for communication with a source of spray-material, and valve-controlled passage means for communicating the first chamber selectively with either said second chamber or the first barrel chamber.

5. A spray-gun including, in combination, a first barrel having a discharge-nozzle and a chamber for motive fluid discharge into the nozzle, a second barrel having a first chamber for communication with a source of motive fluid, a second chamber for communication with a source 01' spray-material, and a passage for communicating said first and second chambers, there being a duct for communicating said first chamber with the chamber of the first barrel, and Valve means in the flrst,chamber for selectively opening or closing communication between the first chamber and said chamber and said duct.

6. A spray-gun including, in combination, a first barrel having a discharge-nozzle and chambers for separate motive fluid and spray-material discharge into the nozzle, a second barrel fixed to the first barrel and having a first chamber communicating with said motive fluid chamber, a second chamber communicating with said spray-material chamber, a third chamber adapted for communication with a source of motive fluid supply, and a fourth chamber adapted for communication with a source of spray-material supply, there being a communicating channel between said third and fourth chambers, and valve-means for opening or closing communication between said first and third chambers and said second and fourth chambers.

7. A spray-gun including, in combination, a first barrel having a discharge-nozzle and chambers for separate motive fluid and spray-material discharge into the nozzle, a second barrel fixed to the first barrel and having a first chamber communicating with said motive fluid chamber, a second chamber communicating with said spray-material chamber, a third chamber adapted for communication with a source of motive fluid supply, and a fourth chamber adapted for communication with a source of spray-material supply, there being a communicating channel between said third and fourth chambers, and valve-means for opening or closing communication between said first and third chambers and said second and fourth chambers, said means comprising valves independently shiftable in said second and fourth chambers, and valve-actuating members oppositely-disposed and yieidingly shiftable on the second barrel.

8. A spray-gun including, in combination, a first barrel having a discharge-nozzle and chambers for separate motive fluid and spray-material discharge into the nozzle, a second barrel fixed to the first barrel and having a chamber adapted for communication with a, source of motive fluid supply and ducts disposed on opposite sides of such chamber andhaving communication with the first barrel chambers respectively, and means comprising a plurality of valves shiftable in the second barrel for selectively communicating the chamber thereof with one or the other of said ducts.

9. A spray-gun including, in combination, a first barrel having a discharge nozzle and separate chambers for motive fluid and spray-material discharge into the nozzle, a second barrel, tubular duct-providing members joining the first and second barrels in parallel relation, the second barrel having a plurality of chambers, some of which have communication through said ducts with the chambers of the first barrel, a block conjoined to the second barrel and having conpassage or between the first duits for communicating other chambers of the second barrel with motive fluid and spray-material supplies, and valve means in the second barrel for controlling communication between the several chambers of the second barrel.

10. A spray-gun including, in combination, a first tubular barrel having a discharge nozzle and separate chambers for motive fluid and spray-material discharge into the nozzle, a second tubular barrel, tubular duct-providing members joining the first and second barrels in parallel relation, the second barrel having a plurality of chambers, some of which have communication through said duets with the chambers of the first barrel, a block conjoined to the second barrel and having conduits for communicating other chambers of the second barrel with motive fluid and spray-material supplies, and

means for controlling communication between the several chambers of the second barrel, said means comprising valves disposed shiftably in the second barrel, caps yieldingly fitted for slidable movement upon the opposite ends of the second barrel, and stems engaging the caps and valves.

11. A spray-gun including, in combination, a tubular barrel closed at an end and divided by a transverse wall to include front andrrear chambers, a conduit lengthwise disposed within the front chamber and spaced from the wall of the barrel, the conduit communicating at one end through the transverse wall with the rear chamber and having a conical head upon its other end provided with a plurality of longitudinally extending radially projecting fins, a nozzle fitted upon the barrel at its opposite end and having an axial discharge orifice aligned with the bore, and substantially abutting the mouth, of the conduit, the nozzle being obliquely contoured upon its inner face for co-operation with said fins in providing a discharge mouth for said front chamber communicating with and surrounding the mouth of the conduit at said orifice, a second barrel conjoined to the first barrel in parallel relation, the second barrel having a first chamber for communication with a source of motive fluid supply, a second chamber for communication with a source of spray-material supply, a third chamber having duct-communication with said front chamber, a fourth chamber having duct communication with said rear chamber, and a communicating channel between said first and second chambers, and valve means shiftable in the first and secondchambers for selectively communicating the first chamber with the third chamber and the second chamber with the fourth chamber.

WILLIAM F. McKEE. 

